Tipping-off apparatus



Sept. 8, 1942. w. J. GEIGER ETAL T I PP ING OFF APPARATUS Filed Aug. 21,1940 5 Sheets-Sheet l lnvewtors WalL'ter J. Geiger, R inald J. Agres,10%

Their" A'ttovneg.

Sept. 8, 1942. w. J. GEIGER EIAL TIPPING OFF APPARATUS Filed Aug. 21,1940 3 Sheets-Sheet 3 as F UJ 15 m m .mlwp F n T d A vwm a .W h xi m andsimilar devices.

Patented Sept. 8, 1942 TIPPING-OFF APPARATUS Walter J. Geiger, ClevelandHeights, and Reginald J. Ayres, University Heights, Ohio, assignors toGeneral Electric Company, a corporation of New York Application August21, 1940, Serial No. 353,524

9 Claims.

Our invention relates to a method and apparatus for sealing the openingsor conduits in the enclosing envelopes of electric lamps and similardevices through which openings or conduits the said devices areexhausted and gas filled. More particularly, our invention relates to aso-called tipping-off method and apparatus for closing and sealing thevitreous exhaust or pump tube which is in communication with theinterior of the envelope of a lamp or similar device.

It is the usual practice to provide the enclosing vitreous envelopes ofelectric lamps, radio,

tubesand other similar devices with a vitreous exhaust tube or othervitreous tubulation extending from said envelope through which theenvelope is exhausted and filled with gas, the said tube or othertubulation being subsequently sealed, usually by fusing it. Somedifiiculty is experienced in performing the sealing or tipping-offoperations at the high speed of operation of the automatic exhaustapparatus with which they must be associated. Such difiiculties are duelargely to variations in thickness and composition of the vitreous wallsof the exhaust passage which affect the rate of heating thereof and thetime required to render them plastic, and to variations in the heatsupplied by the sealing apparatus. However, most difiiculty isexperienced when the lamp or similar device contains gas at greater thanatmospheric pressure as the vitreous walls cannot then be heated to thetemperature ordinarily permitted since they could not withstand the gaspressure without blowing out.

One object of our invention is to provide a method and apparatus fordetermining the heated condition of the vitreous walls of the exhaustpassage in order to permit said passage to be closed and sealed morereadily than heretofore. Such method and apparatus permits more rapidheating of the vitreous walls of the passage andv mechanical working ofsaid walls, since accurate control of the heating operation is affordedand the proper operation of the mechanical means is assured.

Another object of our invention is to provide a method and apparatus forclosing and sealing the exhaust passage in a vitreous portion of adevice having a gas filling greater than the subatmospheric pressuresnormally used for lamps The difilcultywith which the exhaust passa e isclosed increases greatly when the gas pressure approaches and exceedsatmospheric pressure as some mechanical means must be provided to bringthe walls of said passage together. The mechanical means must be timedto operate after the vitreous walls of the passage are heated to adegree which renders them plastic and workable but before said walls areheated to a degree where they no longer have suflicient strength towithstand the gas pressure within the envelope. The period of timeduring which the vitreous walls are between these diiierent degrees ofheat is extremely short in high speed apparatus and the dimculty ofdetermining the condition thereof is greatly increased. When the gaspressure in the device approaches atmospheric pressure said device mustordinarily be cooled before the tipping-off operation is brought aboutin order to reduce the pressure as much as possible. To operate in thismanner ordinarily takes up two of the sixteen stations of the exhaustapparatus and limits the production of said apparatus. Our inventionprovides a method and apparatus for ascertaining the individual heatconditions and proper mechanical pinching apparatus under theseparticular conditions of operation.

Another object of our invention is to provide a method and apparatus forclosing and sealing a portion of the exhaust passage without actualcontact with the heated vitreous walls thereof.

A still further object of our invention is to provide apparatus forclosing, sealing and tipping-off the vitreous exhaust tubes extendingfrom the envelopes of such devices at a high rate of speed, incombination with the high speed rotating type of exhaust apparatus.

Other objects and advantages of our invention will appear from thefollowing detailed description of species thereof and from the drawmgs.

In the drawings, Fig. 1 is a plan view of one species of tipping-offapparatus comprising our invention in combination with the adjacentportions of an exhausting and gas filling apparatus; Fig. 2 is a sideelevation of the essential parts of the tipping-off apparatus on alarger scale; Fig. 3 is a perspective view of lamp positioning mechanismassociated therewith; Fig. 4

is an end elevation of pinching and operating portions of our apparatus;Fig. 5 is a side elevation of the pinching portion of the apparatus fromwhich portions have been broken away; Fig. 6 is a perspective view of aclutch forming part of the operating portion of the apparatus; Fig. 7 isa. perspective view oflamp supporting and lifting portions of amodification of our invention; Fig. 8 is a side elevation of a secondmodification thereof; and Fig. 9 is a perspective view of an exhausttube sealed by said second modification.

In Fig. 1, four adjacent heads III of the exhausting and gas fillingapparatus appear, although it will be understood that duplicate headsare mounted at regular intervals in a circular path adjacent theperiphery of the turret II. Each of the heads I accommodates asingleincandescent lamp I2, in this instance, and provides an exhaust port forreceiving the vitreous exhaust tube I3 of said lamp I2 as shown in Fig.2. The turret II is indexed in a counter-clockwise direction andadvances the heads I0 from station A, the loading station, throughstation B and others (not shown) at which the exhausting and gas fillingoperations are-automatically brought about, and finally carries saidhead I0 to stations C and D- Such apparatus is preferably that disclosedin the Patterson Patent 1,662,045 and provides a driven shaft (notshown) below the turret I I for operating the parts thereof in propertime relation to the indexing movements of said turret II.

A lamp I2 is placed in the head In at station A by a movement wh chinserts the end of the exhaust tube I3 (F 2) into the central openingsin the guide I4 and the compression rubber I5. the movement be ngcompleted when said end rests on the shoulder I6 of the body I I of saidhead If). The compress on rubber I engages the exhaust tube I3 only withsufficient pressure to keep the lamp I2 in an upright position and isnot caused to seal sa d tube I3 in the body I1 unt l stat on B isrem-had.

In the indexing movement which follows, said lamp I2 is carried intostation B and into the space between the opposite legs of the yoke I8 asindicated in Fig. 3. The yoke I8 is a portion of a positioning means atthis station which lifts and thereby re-positions said lamp I2 so thatthe lower end of the seal I9, the point of reference, is at a definitelevel. Such apparatus is not always required as the length of theexhaust tube I3 can often be controlled with sufficient accuracy toestablish the position of said lamp I2 as desired. The said positioningmeans essentially comprises plates 2lI-2I on the opposite legs of theyoke I8 which are raised to a fixed level during every cycle ofoperation of said means. The plates 202I are located at opposite sidesof the path of movement of the exhaust tube I3 and are actuated througha corresponding movement of the slide 22 which is connected to said yokeI8 through the rod 23. The slide 22 is located in the ways of thebracket 2i extending from a portion of the frame of the exhaust machinebelow the turret II and takes a position determined by the particularportion of the wedge shaped cam 25 located below the roller 26 on thelower end of said slide. The cam 25 is mounted on the arm 21 attached tothe vertical shaft 28 in the bracket 24 and is actuated by the usualform of cam-operated means (not shown) on a driven shaft of the exhaustmachine connected to said arm 21 through rod 29.

The plates III-2| engage the lower surface of the seal. I 9 of the lampI 2 and hold said lamp I2 in this newly established position until thecompression rubber I5 is squeezed to grip the exhaust tube l3. Thislatter operation is performed by turning -the cap 30 so that it isscrewed down on the body I! of the head I0 and causes the guide I4 tosqueeze the compression rubber I 5 and is brought about eithenby manualadjustment of the cam 3| on said cap 30 or by mechanical adjustment ofsaid cam 3 I by a portion (not shown) of said exhaust machine. Thecompression rubber I5 expands laterally so that it seals the exhausttube I3 in the body I! and grips said tube I3 with sufficient force toresist its withdrawal. Both the plates 20 and 2i are returned to theirformer position before the head I0 and lamp I2 are indexed from thisstation. In instances where the exhaust machine provides a head havingrubber connection means of different construction into which the exhausttube I3 must be forced, the upward motion of the positioning means maybe sufficient to move the lamp I2.

Succeeding indexing movements of the turret I I carry the lamp I2 toother stations for periods which permit it to be repeatedly exhaustedand flushed, and finally exhausted and gas filled in the usual manner,and finally carries said head IIJ to station C. While at this station,C, that portion of the exhaust tube I3 which is to be closed and sealedis preheated by the flames from the burners 32 and 33 which normally lieout of the path of movement thereof but are carried into operativerelation to the exhaust tube I3 between the indexing movements of thehead I 0. The burners 32 and 33 are mounted on opposite ends of theU-shaped manifold 34 and are moved into position by the rocking motionof the shaft 35 to which said manifold 34 is connected by the clamp 36and the vertically disposed rod 31. The shaft 35, in turn, is held bythe sidewardly extending arm 38 of the bracket 39 and is operatedthrough arm 40, rod 4| and lever 42 which are portions of means actuatedby a cam (not shown) on a driven shaft of the exhaust apparatus. Thebracket 39 is a stationary member, as it is mounted on a portion of theframe (not shown) of the exhaust apparatus below the turret II.

In the course of the movement of the burners 32 and 33 to the operativeposition, the metal shield 43, which is attached to the top surfacethereof, is carried under the lamp I2 and into engagement with the lowerextremities of the seal I9 thereof which prevent further motion andpositions the burners 3233 longitudinally along the exhaust tube I3.positioning action, the shield 43 also serves to direct the splash andheat of the pre-heating flames away from the upper portion -of theexhaust tub I3 and the other parts of the lamp I2. The gas and airmixture used by the burners 32 and 33 in this instance is conducted tothe manifold 34 through the flexible hose 44.

The period of operation of the burners 32 and 33 is relatively short andthe exhaust tube I3 is heated to some point below that at which itbecomes plastic and would change shape due to a difference betweeninternal and atmospheric pressures. The lamp I2 shown contains gas atgreater than atmospheric pressure and the heating of the exhaust tube I3must not be such that said gas pressure can cause it to bulge. In everyinstance, the gas pressure within the lamp I2 is at a greater pressurethan it will finally be because of the heat said lamp I2 contains atthis time.

After a predetermined period at station C, the exhaust head I0 carriessaid lamp I2 to station D where the pre-heated portion of the exhausttube I3 is again heated but this time only the exact amount required tobring said tube I3 to In addition to its a very definite degree ofplasticity. The exhaust tube I3 must not soften to such apoint that thegas pressure within the lamp I2 can cause an opening to be blowntherethrough or cause a substantial change in shape thereof but must becarried to such a point that it can be pinched shut by the jaws 45-46(Figs. 1 and 2). To control the heating operation this closely isextremely difficult and necessitates separate control for each case dueto variations in the amount of heat in the exhaust tube I3 at the startof the tipping operation and the heating effect of each of the differentburners and differences in the size, distribution and composition ofsaid exhaust tube l3. In many instances, the rate of indexing theexhaust heads I8 is so rapid that additional pre-heating burners must beplaced at the station ahead of station C since the operating period ofthe apparatus at station D is shared by the burners 41-48 and thepinching jaws 45-46. The burners 41-48, as shown in Figs. 1 and 4, areeach mounted on one end of rigid pipes .49 and 58, respectively, whichpipes are held by a plurality of arms extending from the metal block 52which in turn is.supported by the metal supports 53 on the extendingportion 54 of the frame of the exhaust machine. The combustible gasmixture enters the opposite ends of the pipes 48-58 through therubberhose 55, and preferably is made up of gases producing more heatthan in prior instances. The burners 41-48 andpipes 49-58 are stationarymembers since they are located out of the path of movement of the headI8 and lamp I2 from station C to the unloading station D.

The heating period of the burners 41-48 is controlled by means engagingthe lamp |2 during its movement to station D and comprises the pressuremember or cup 56, which receives the upper portion of the exhaust tubeI3 and the seal I9 of said lamp I2, and the resilient clip or holder 51which receives the neck of the lamp bulb at the end of said movement.The cup 56 is mounted on the outer end of the arm 58 and is held at aposition which permits the seal I8 to pass over the slotted bottom 59thereof and is immediately moved up until said bottom 59 is against thelower extremity of said seal I9. The arm 58 is attached to the shaft 68which is supported by the arms 6I-6I on opposite sides of the block 52and is actuated by the arm 62 on the end of said shaft 68 which isconnected to the rod 63 and the spring 64. The rod 63 is the onlyillustrated portion of the cam controlled operating means actuated bythe main drive shaft of the exhaust apparatus and at this time adjustssaid rod 63 so that the contracting force of the spring 64 isresponsible for the movements of the cup 56. In this manner, a knownamount of upward pressure is exerted against the cup 56 and the upperportion of the lamp I2, and a known tension is placed in the exhausttube I3. Very soon thereafter, the exhaust tube I3 softens to a pointwhere it is lengthened by the tension under which it is kept, and theresulting upward movement of said cup 56 carries the end of the screw 65on the arm 62 (see Fig. 5) downward against the control pin 66 f thecompletely enclosed switch 61. The said switch 61 is a commercial typeof single-pole single-throw switch made by The Micro Switch Corporationof Freeport, Illinois.

The switch 81 indirectly controls the operation of the squeezing orpinching jaws 45-46 and,

when closed in this manner, causes the solenoid 68 (Fig. 4) to bringabout the engagement of the clutch 69 of the operating apparatus forsaid jaws. At this time, the exhaust tube I3 has not softenedsufliciently to permit any gas pressure in the lamp I2 to materiallyexpand said exhaust tube I3 but said tube I3 has softened to a pointwhere it can be worked satisfactorily by the jaws 45-46. In instanceswhere the gas pressure in the lamp I2 is so low as to be belowatmospheric pressure, this apparatus is adjusted so that the pinching orsqueezing occurs when the exhaust tub I3 is softened the desired degree.

The movable armature 18 actuated by the solenoid 68 is connected to thearm 1| of the clutch 68 by the bar 12 and is raised by said solenoid 68until the arm 1| takes the position shown in Fig. 6 and the movable dog13 is permitted to shift and engage the teeth 14 on the driven clutchdisk 15. The arm 1| is pivoted on the pin 16 extending from the bracket11 on one portion of the frame and is lifted from the transverse slot 18in the dog 13 so that the xpansion of the spring 19 contained within awell therein can move said dog 13 longitudinally in ways in the idlingdisc 88 of the clutch 69. The spring 19 also bears against a pin 8|extending outward into said ways in the idling disc 88 and quicklyadvances said dog 13 beyond the face of said disc 68 and into the pathof one of the teeth 14 on the adjacent face of the driven disc 15. Theidling disc 88 is fastened to a shaft 82 supported by the bracket 83attached to a portion of the frame while the corresponding driven disc15 is fastened to the shaft 84 supported by the bracket 65. The drivendisc 15 receives its rotative force from an electric motor and speedreducer (not shown) which are connected thereto through the chain 86 andsprocket 61 and provides a source of power rotating faster than thedrive shaft of the exhaust apparatus.

The first result of the engagement of the clutch 69 is to move the jaws45-46 radially inward of the turret into operative relation to theexhaust tube I3 since both jaws are pivotally mounted on the pins 88-88(Fig. 1) extending from the slide 89 (Fig. 4) and said slide 89 and thesecondary slide 98 (Figs. 1 and 4) are moved forward as a unit by thelever 8| which is pivotallyconnected to the secondary slide 98 by pin8|. The lever 9| is pivoted on the pin 92 extending from the metalsuports 53 and is actuated by the crank motion of the pin 93 in the disc84 on shaft 82 which motion is transferred to the lever 9| through therod 85. The slide 89 moves forward until the nuts 96 on the stud 91extending from the end thereof engage the yoke 98 on the end of .theblock 52 whereupon the continued pressure of the lever 9| moves thesub-slide 88 in the ways in slide 89 causing the jaws 45-46 to pivot andclose. The sub-slide 88 is held in these ways by the cover plate 99 and.when moved separately from slide 98. respositions the post I88,

which extends upward through a slot in the cover plate 99, with respectto the slide 89 and operates the toggle joint formed by the links |'|Ito therebvpivot and close the jaws 45-45. The r dially inward movementof post I88 stretches the spring I82 extending between post I88 and thepost I83 extending from the cover plate 98, and causes the jaws 45 and46 to bring the dies |84 |84' into engagement with the heated and nowplastic portion of the exhaust tube I3. The dies I84-I84 squeeze andpinch the walls of the exhaust tube I3 together until the exhaustpassage therethrough is completely blocked off the said dies pressing acomparatively large portion of the opposite walls of said tube I3together so that a verystrong and reliable seal is formed. The walls ofthe exhaust tube I3 are sufllciently plastic to seal together and arevery quickly v cross bar I09 which causes them to operate as a singleunit. Operation of the arms II--I08 is brought about by the separatemotion of the subslide 00 in that it carries the cam I I0 against theend III of arm I08 and forces it upward, thus lowering the shields II06.

The dies I04-I04 are preferably provided with matching ridges II2 whichcan be caused either to groove the exhaust tube I3 so that it can bebroken off at a predetermined point or to shear off said exhaust tube I3as shown. The latter arrangement is preferred in that the lamp I2 isreleased from the head I0 at this time and, while still held by the clip51, is lifted by further movement of said clip 51 and cup 56 caused bythe further contraction of the spring 64 until the lamp is placed in adischarge chute (not shown) located above this apparatus.

The apparatus is immediately returned to its original position by theclock-wise movement of the lever 9I on the downward stroke of the pin93. A repeat operation would then occur except that the mechanismcontrolled by the armature I0 of solenoid 68 is disconnected from theclutch 69 which automatically disengages and stops said pin 93 at thebottom of its stroke. The disconnecting action is brought about by theengagement of the cam II3 (see Fig. 6) on the idling disc 80 of saidclutch 69 with the roller II 4 on the end of the lever II5 which isconnected to bar I2 (which is, in turn, connected to armature I0 ofsolenoid 68) through the link H6 and which shifts said bar I2 so thatthe vertically elongated portion of the inverted L-shaped slot I I1 isabout the pin H8. The arm II is then forced down by the expansion of thespring II9 which is located between it and the immediate lower surfaceof the frame and further rotation of the idling disc 80 carries arelatively narrow exposed portion of the groove 18 in th dog I3 againstthe wedge shaped end of arm 1|. Still further movement of the idlingdisc 80 causes the end of the arm II to force the end of the dog I3outward and the opposite end away from the teeth I4 of the driven disc15. At the end of the movement, the dog I3 engages the shoulder I20 onthe arm II and stops all movement and the switch 61 is again opened sothat the solenoid 68 permits the rod I2 to fall to its former position.The cam H3 in this interval passes beyond the roller II 4 and the fullpressure of the leaf spring I2I which extends down from the immediatframe portion is free to move the lever II 5 and rod I2 back to itsearlier position as the pin H8 is again located in the wider or lateralportion of the slot III. In the return movement of the sub-slide 90, thecam III) is carried away from the end III of lever I08 and other meansare provided for keeping the shields IDS-I06 in position before theburners 4I-48. Such means consists of the rod I22 (Fig. 4) which extendsbetween lever I01 and the collar I23 on the vertically disposed push rodI24, and other means actuated by a cam (not shown) on a driven shaft ofthe exhaust machine which moves the push rod I24. After this particularhead I0 is indexed out of station D and the succeeding head I0 is aboutto move into said station, the push rod I24 is re-adjusted so that'theshields IDS-I06 are moved upward and no longer cut off the flames fromthe bumers 4I-48. The exhaust head I0 is then indexed to the loadingstation where the cap 30 is turned so as to release the pressure on thecompression rubber I5, and the stub of the exhaust tube I3 is takentherefrom.

In instances when it is not desired to remove the lamp I2 directly-afterthe pinching operation as when the exhaust tube I3 is not completelysheared off, it is preferred that the modification of the apparatusshown in Fig. 7 be used. The modification provides a movable plate I25in combination with each of the exhaust ports I0 which limits the extentto which the exhaust tube I3 can be inserted therein and definitelyestablishes the position of the lamp l2. The lamp I2, in this instance,is pushed down, upon insertion, until the seal I9 rests on the asbestospad I26 on the plate I25 at which-time it is also located between thethree padded pins I2I of holding means also combined with the exhaustports I0. The plate I25 is mounted on the arm I28 which is pivotallymounted on the pin I29 extending from the bracket I30 whereas the pinsI21 are attached to the plate I3I which is attached to the upper part ofthe bracket I30. The bracket I30 in turn is mounted on th upper end of apost I32 held by an extending portion I33 of the turret II adjacent theexhaust port I0, The position of th plate I25 must be established sothat it will be properly aligned with the other portions of my apparatuswhen indexed into the station occupied thereby and is under the controlof the stop screw I34 carried by the extending portion I33 of the turretI I against which the bottom of the bracket I28 rests. A helical springI35 is located between plate I25 and plate I3I in order to keep saidplate I25 in the lower position.

That portion of the modified apparatus mounted on the turret II is of nofurther use until all exhausting and gas filling operations have beencompleted and the exhaust port' I0 has been indexed into a stationcorresponding to station D. At this time, the exhaust tube I3 is heatedby the flames from burners (not shown) corresponding to those used inthe prior instance and is placed under tension by the upward movement ofthe plate I25 which is actuated by a corresponding motion of arm I36carrying said arm I36 into engagement with the roller I3I on the pin I38in outer portion of said plate I25. The arm I36 corresponds to the arm58 of the prior apparatus in that it applies a definite force to theexhaust tube I3 which causes it to stretch when it is sufficientlyplastic to be worked and in that it causes the pinching jaws (not shown)to close at the moment the stretch occurs. The bumers 4'I--48 and theoperating means for arm 58 are preferably used in combination with thislatter apparatus although said burners must be arranged in a differentmanner to be out of the path of movement of the apparatus 0n the turretII as it is moved to and from the modified apparatus. The extent towhich the exhaust tube I3 is stretched is governed by the stop screw I39in the bracket I30 which limits the upward movement of'the plat I25. Thepinching laws are also preferably those of the prior apparatus but areonly closed such an amount that the exhaust tube is flattened andgrooved, and not until it is completely sheared off. The'posts I21 andthe plate I25 must then hold and support the lamp I2 which isimmediately indexed from this station. During the indexing movement, theroller I31 passes onto the track I40 which is arranged so that the plateI25 i kept up against the seal I9 of said lamp l2. The usual form ofmechanisms for unloading the lamp I2 are sufficiently strong toautomatically cause the exhaust tube I3 to be broken off at the weakenedor grooved point.

The modification or our invention shown in Fig. 8 is located adjacentthe tipping-off station of the exhaust and ga filling apparatus and iscomprised of a plurality of burners I4I (only one of which appears inthe drawings) which direct flames against the exhaust tube I3. Theburners I4I heat a selected portion of said exhaust tube I3 adjacent theseal I9 of the lamp I2 and can, if desired, be movably mounted so as tobe shifted to and from operative relation to said exhaust tube I3 verymuch as in our other apparatus (Fig. 1). In this instance the exhausttube I3 is subjected to a definit tortional strain by the rotationalefforts of the vacuum cup I42 which engages the top of the lamp I2 sothat when the said tube finally reaches a temperature where it is nolonger strong enough to resist the rotational force, it then starts totwist. The twisting movement indicates that the exhaust tub I3 is heatedto a safe temperature to be tipped off and is continued until the lampI2 i turned a number of complete revolutions and an appreciable lengthof said exhaust tube I3 is twisted. At the moment the lamp I2 and thevacuum cup I42 begin to rotate, it is preferred that the heating effectof the burners I4I be discontinued either by a reduction in the amountof the combustible gas mixture supplied thereto or by the insertion ofshields between said burners MI and the exhaust tub I3. The walls of theexhaust tube I3 are, at such times, sufliciently heated to be drawn intocontact with each other by the twisting motion and seal to each otherbefore cooling takes place. The twisting force is very definitelyestablished in that it results in the deformation of the exhaust tube I3which is the controlling element in the method and is therefore directlyresponsible for the timing of the operations of the apparatus whichclose the passage in said exhaust tube I3.

The period of operation of the burners HI and the cup I42 starts whenthe turret II carries the exhaust port I holding the lamp I2 to thestation shown as the exhaust tube I3 is then placed in operativerelation to said burners HI, and the cup I42 is immediately lowered ontothe lamp I2. The vertical movement of the cup I42 is, however,separately produced and is brought about through a correspondingmovement of the spindle I43, the arm I44 and the vertical standard I45all of which are fastened together so that they move as a unit. Thestandard I45 is located out beyond the edge of the turret II and itdirectly engages apparatus (not shown) actuated by the cam shaft (alsonot shown) of the exhausting and gas filling apparatus below the turretII which makes it possible to carry the cup 2 to and from engagementwith the lamp I2 in proper time relation to the movements of the exhaustport I0. The cup I42 must grip the top of the lamp I2 with suflicienttenacity to cause it to turn therewith and is therefore constructed soas to seat firmly on the top of the lamp I2 and pull thereon with thesuction force of vacuum. The universal joint formed by the head I46 ofsaid cup I42 and the flared fitting I41 on the end of said spindle I43permits said cup I42 to adjust itself to the top of the lamp I2 whereasthe gasket I40 of asbestos or the like seals the juncture between saidcup I42 and the lamp I2. A spring I49. located between a post in thespindle I43 and a second post I50 in the head I46 of the cup I42 holdssaid cup I42 in place during the intervals it is not in contact with thelamp I2. The spring I49 is located in the hollow center of the spindleI43 which provides for the vacuum connection to the cup I42 in that itis closed at the top by the plug I5I and is connected to the chamber I52in the arm I44 by the openings I53 in the side walls of the spindle.Stufling boxes I54 at opposite ends of the opening in the arm I44holding the spindle I43 prevent leakage thereabout whereas the pipenipple I55 and the flexible hose I56 connect the vacuum source (notshown) to said chamber I62.

The rotational force with which the lamp I2 is turned is transferred tothe cup I42 from the spindle I43 by the pin I50 which is carried by thehead I46 of the former and which is located in a slot in the fitting I41of the latter. Said force originates in the shaft I51 which is coupledto said spindle I 43 through the bevel gears I68 and I59. The shaft I51is held in bearings in the arm I44 and is turned by the gravitationalpull of the weight I60 which hangs from the rope i6! wound about thedrum I62 on the outer end of said shaft I51. The size of the weightItiu, of course, can be varied so as to produce the definite rotationalforce desired and is selected after consideration of the gas pressure inthe lamp, the size and strength of the exhaust tube and the 'rapiditywith which said exhaust tube is heated.

As hereinbefore stated, the exhaust tube I3 must not be heated until itno longer has suflicient strength to remain intact but must be heated tosome point where it can be worked. The manner in which the apparatusoperates must also be taken into account and in some instances it may bedesirable to use an exhaust tube of greater than normal wall thicknessto properly meet all operating conditions.

Both the suction and the twisting operations are desirable only when thecup I42 is in engagement with the lamp I2 and means can be provided incombination with the cam shaft of the exhausting and gas fillingapparatus for confining these operations to the proper periods. Avertical shaft I63 within the hollow standard I45 and the inter-meshingbevel gears I64 and I65 provide the means of connecting the cam shaftactuated means to the shaft I51 of the twist producing means. The shaftI63 and the gears I64 and I65 also provide means of turning the drum I62and rewinding the rope I61 after each succeeding cycle of operation. Theexhaust tube I3 is twisted a sumcient number of times to cause anappreciable portion of said exhaust tube I3 to be drawn together, asshown in Fig. 9, and

ordinarily must be twisted four to ten times to duce this operation.Such means can be operated' from a cam on the cam shaft-of theexhausting and gas filling apparatus and can actuate the hollow standardI45. The exhausttube I! now is drawn down to such a size that it may nothave suillclent strength to support the lamp I2 and the plate I66 andposts I61 which extend therefrom are depended upon to support said lampI2. The posts I61, of which there are three in number, are. locatedabout the neck of the lamp I! as in the prior instance shown in Fig. 7and are fastened to the plate I66 which. in turn, is attached to the armI68. Said arm I68 is pivotally attached to the block I69 by the pin I10in the manner of the arm I28 in Fig. 7 and is swung upward so that plateIE6 is kept against the seal I! of the lamp I2 by the expansion of thespring I. A well in the arm I68 is provided to hold the spring I'llwhich butts against the block I69. After the closure is made bytwisting. the exhaust tube I! can be severed by cold cutting or byfires, depending on the shape of tip desired. Either of these operationscan occur at a succeeding station taken by the head ll if desired.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. The method of sealing an exhaust tube extending from a sealedenvelope containing gas at a pressure above that of the surroundingatmosphere which comprises heating a portion of the exhaust tube whilethe said tube portion is exposed to the said surrounding atmosphere,mechanically exerting on said tube, while it is being heated,'anexternal force to produce a strain in said tube of sufficient magnitudeto rapidly deform the heated portion of the tube when it becomessufliciently plastic to be thus deformed but before said tube portionbecomes sufficiently plastic to be ruptured by the internal gaspressure, and thereafter preventing additional heating of said tubewhich would render it sufficiently plastic to be ruptured by saidinternal gas pressure.

2. The method of sealing an exhaust tube extending from a sealedenvelope containing gas at a pressure above that of the surroundingatmosphere which comprises heating a portion of the exhaust tube whilethe said tube portion is exposed to the said surrounding atmosphere.mechanically exerting on said tube, while it is being heated. anexternal force to produce a strain in said tube of sufficient magnitudeto rapidly deform the heated portion of the tube when it becomessufliciently plastic to be thus deformed .but before said tube portionbecomes sufficiently plastic to be ruptured by the internal gaspressure, and squeezing the said heated and deformed tube portionimmediately after the deformation has started so as to seal it andpreventing additional heating of said tube which would render itsufficiently plastic to be ruptured by said internal gas pressure.

3. The method of sealing an exhaust tube extending from a sealedenvelope containing gas at a pressure above that of the surroundingatmosphere which comprises heating a portion of the exhaust tube whilethe said tube portion is exposed to the said surrounding atmosphere,mechanically exerting on said tube, while it is being heated, anexternal force to produce a twisting strain in said tube of sufficientmagnitude to rapidly deform the heated portion of the tube when itbecomes sumciently plastic to be thus deformed but before said tubeportion becomes sufflciently plastic to be ruptured by the internal gaspressure, and thereafter preventing additional heating of said tubewhich would render it sumciently plastic to be ruptured by said internalgas pressure.

4. Apparatus for sealing an exhaust tube extending from a sealedenvelope containing gas at a pressure above that of the surroundingatmosphere comprising means for heating a portion of said exhaust tubewhile the said tube portion is exposed to the said surroundingatmosphere, mechanical means exterior of said envelope exerting acontinuous strain on said tube while it is being heated tending todeform it, the said strain being of sufficient magnitude to rapidlydeform the heated portion of the tube when it becomes sufllcientlyplastic to be thus defor'med but before said tube portion becomessufficiently plastic to be ruptured by the internal gas pressure, andmeans for preventing additional heating of said tube which would renderit sumciently plastic to be ruptured by said internal gas pressure.

5. Apparatus for sealing an exhaust tube extending from a sealedenvelope containing gas at a pressure above that of the surroundingatmosphere comprising means for heating a portion of said exhaust tube,while the said tube portion is exposed to the said surroundingatmosphere, and mechanical means exterior of said envelope exerting acontinuous strain on said tube while it is being heated tending todeform it, the said strain being of suflicient magnitude to rapidlydeform the heated portion of the tube when it becomes sufficientlyplastic to be thus deformed but before said tube portion becomessufficiently plastic to be ruptured by the internal gas pressure,clamping jaws arranged to pinch the heated and deformed tube portionimmediately upon deformation thereof, means operative upon deformationof said tube portion for causing said clamping jaws to close upon saidtube portion, and means for preventing additional heating of said tubewhich would render it sufliciently plastic to be ruptured by saidinternal gas pressure.

6. Apparatus for sealing an exhaust tube extending from a sealedenvelope containing gas at a pressure above that of the surroundingatmosphere comprising means for heating a portion of said exhaust tube,mechanical means exterior of said envelope exerting a continuous strainon said tube while it is being heated tending to deform it, the saidstrain being of sufficient magnitude to rapidly deform the heatedportion of the tube before said tube portion becomes suflicientlyplastic to be ruptured by the internal gas pressure, clamping jawsarranged to pinch the heated and deformed tube portion immediately upondeformation thereof, and means actuated by movement of the saidmechanical strain-exerting means for causing said clamping jaws to closeupon said tube portion.

7. Apparatus for sealing an exhaust tube extending from a sealedenvelope containing gas at a pressure above that of the surroundingatmosphere comprising means for. heating a portion of said exhaust tube,mechanical means exterior of said envelope exerting a continuous strainon said tube while it is being heated tending to stretch it, the saidstrain being of sufficient magnitude to rapidly stretch the heatedportion of the tube before said tube portion becomes sufficientlyplastic to be ruptured by the internal gaspressure, clamping jawsarranged to pinch the heated and stretched tube portion immediately uponstretching thereof, and means actuated by movement of the saidmechanical strainexerting means for causing said clamping jaws to closeupon said tube portion.

8. Apparatus for sealing an exhaust tube extending from a sealedenvelope comprising means for, supporting and rigidly gripping the endof said exhaust tube, means for heating a portion of said exhaust tube,a pressure member engaging said envelope, a lever carrying said pressuremember at one end, spring means engaging the opposite end of said leverand resiliently urging the pressure member in a direction tending tostretch the exhaust tube while it is being heated. clamping jawsarranged to pinch the heated and stretched tube portion immediately uponstretch- 9. Apparatus for sealing an exhaust tube extending from asealed envelope containing gas ing thereof, and means for causing saidclampat a pressure above that of the surrounding atmosphere comprising.means for supporting and rigidly gripping the end of said exhaust tube,means for heating a portion of said exhaust tube while the said tubeportion is exposed to the said surrounding atmosphere, means engagingsaid bulb and tending to twist the exhaust tube while it is beingheated. the twisting force of said last-named means being of sufficientmagnitude to rapidly twist and seal ofi the heated portion of the tubewhen it becomes sufiiciently plastic to be thus deformed but before saidtube portion becomes sufiiciently plastic to be ruptured by the internalgas pressure, and means for preventing additional heating of said tubewhich would render it sumciently plastic to be ruptured by said internalgas pressure.

WALTER. J. GEIGER. REGINALD J. AYRES.

calm-numor cdmcndn. I Patent Io. =2,295,o5h; 7 September 3,19 2.

WALTER "J. enema, 31' AL.

It is hereby certified 'thit error appears .in the pr 1 ntedapecliticetion of the 'above numbered patent requirfrng correctionfellows :1 Page L-eec- 0nd column; line 65, for-slide 90" reed el1de89-; line 61;, utter upward mart "from slide 90 and that the audmettera'Patent should be read with this correction therein that the seine mayconform to the record of the case, in the Petent Office.

Signed m1 sealed this in; day, or December, A. n.-19LL2'.

I I Henry-Van'Airedale", v (Seal) Acting Commissioner of Patents.

